摘要:

Objectives:Animal studies have shown that the elevation of plasma glutamate levels increase cerebral edema formation whenever the blood-brain barrier is disturbed. Therefore, changes in plasma glutamate levels as influenced by the administration of a glutamate-containing amino acid solution were investigated in neurosurgical patients.Design:Prospective, descriptive study.Setting:Eight-bed neurosurgical intensive care unit in a university hospital.Patients:Twenty-three neurosurgical patients requiring parenteral nutrition.Interventions:Parenteral nutrition was begun 24 hrs after craniotomy. Patients receiving a glutamate-containing amino acid solution (3.75 g/L glutamate) were compared with patients infused with a glutamate-free solution.Measurements and Main Results:Arterial plasma and urine amino acids were analyzed using high-performance liquid chromatography. Administration of a glutamate-containing solution doubled plasma glutamate levels in neurosurgical patients (from 53.3 ± 9.8 μM [preinfusion] to 98.5 ± 18.7 μM [after 4 hrs of infusion];p< 0.001), whereas no elevation was seen when infusing a glutamate-free solution (from 52.3 ± 7.3 [1 hr of infusion] to 53.6 ± 6.4 μM [4 hrs of infusion]). Upon terminating the glutamate-containing infusion, arterial plasma glutamate levels decreased immediately (from 120 ± 13.2 μM to 81.2 ± 19.5 μM). Glutamate as infused in excess appears to exceed a renal threshold and is eliminated renally.Conclusions:As shown in animal models, administration of a glutamate-containing amino acid solution significantly increased plasma glutamate levels. Because such an increase in plasma glutamate levels could aggravate cerebral edema formation, glutamate-containing amino acid solutions cannot be recommended for patients with a disturbed blood-brain barrier.

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Objective:To measure admission cortisol and adrenocorticotrophic hormone (ACTH) levels in children with meningococcal disease to try and determine the prevalence of adrenal insufficiency.Design:Prospective observational study.Setting:Pediatric departments of four hospitals in Merseyside, United Kingdom.Patients:Ninety-six children with meningococcal disease; 29 with hypotension, ten of whom died.Measurements and Main Results:Admission cortisol, ACTH, and proinflammatory cytokine levels were measured. Serial cortisol levels also were measured during the first 48 hrs.Significantly lower cortisol levels were found in those who died compared with survivors. Significantly higher ACTH levels also were found in those who died. However, no child had a cortisol level <5 μg/dL (<138 nmol/L) implying definite adrenal insufficiency. Three of 29 children with hypotension had plasma cortisol levels implying possible adrenal insufficiency (<18 μg/dL [<497 nmol/L]), but high ACTH levels were only found in one of those three.Cortisol levels decreased significantly after antibiotic treatment, unless steroid therapy was administered. ACTH levels did not correlate with cortisol or proinflammatory cytokine levels.Conclusions:Children with meningococcal disease have a wide range of initial plasma cortisol levels, with lower levels found in those who die. Many factors may affect cortisol levels, but adrenal insufficiency is probably uncommon.

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Objective:To determine the efficacy of switching to subcutaneous fentanyl with or without midazolam to prevent withdrawal after prolonged sedation in children in the pediatric intensive care unit (PICU).Design:Retrospective review of hospital records.Setting:Tertiary care center, PICU.Patients:The cohort for the study included patients who had received subcutaneous fentanyl with or without midazolam to prevent withdrawal after prolonged sedation in the PICU.Measurements and Main Results:Subcutaneous fentanyl with or without midazolam was administered to nine patients ranging in age from 3 to 7 yrs (mean, 4.4 ± 1.8 yrs) and ranging in weight from 11 to 31 kg (mean, 20.1 ± 6.8 kg). All patients required prolonged administration of fentanyl with or without midazolam during mechanical ventilation for respiratory failure. The starting infusion rate for subcutaneous fentanyl varied from 5 to 9 μg/kg/hr (mean, 7.1 ± 1.4 μg/kg/hr). Four patients also received subcutaneous midazolam at a rate of 0.15 to 0.3 mg/kg/hr (mean, 0.24 mg/kg/hr). Subcutaneous access was maintained for 3-7 days (mean, 5.7 ± 1.4 days) in the nine patients. No problems with the subcutaneous access were noted during treatment. The fentanyl infusion was decreased by 1 μg/kg/hr every 12-24 hrs and the midazolam infusion was decreased by 0.05 mg/kg/hr every 12-24 hrs. No patient demonstrated signs of symptoms of moderate to severe withdrawal.Conclusion:The subcutaneous route provides an effective alternative to intravenous administration. It allows for gradual weaning from sedative/analgesic agents after prolonged sedation while eliminating the need to maintain intravenous access.

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Objective:To describe structural models of intermediate care units used for critically ill patients.Data Sources:Three multidisciplinary units with varying structures and functions of intermediate care areas (ICAs) are described.Data Synthesis:Advantages and limitations for each of the three models are outlined. The structural models described are the conventional isolated ICA model, the parallel model, and the integrated model of ICA.Conclusion:Each structural model has advantages and limitations. Selection of the appropriate ICA model for an institution depends on the specific circumstances and needs of the institution. Each of the three models can facilitate improved utilization of critical care resources.

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Objective:To determine a meta-analytical definition of the discriminant power of Ranson's signs in the prediction of acute pancreatitis severity and outcome, and of their information content, also compared with clinical judgment.Data Sources:Two hundred eleven studies since 1974, reporting any predictive system for acute pancreatitis (MEDLINE by various Medical Subject Headings in MEDLARS, Current Contents, Medscape, Virtual Hospital, and other on-line medical services).Study Selection:One hundred ten studies reporting clinical use of Ranson's signs were retained. A quality index was calculated for each study. A selection was made according to inclusion criteria, separately for prediction of severity (19 studies; group S) and prognosis (10 studies; group P). Six other studies reporting clinical judgment results were also selected (group C).Data Extraction:Sensitivity and specificity values were extracted. Effect sizes were calculated and summarized by the inverse variance-weighted method. Categorical models were studied by analysis of variance. Publication bias was sought by correlation test and analysis of variance. Summary receiver operating characteristic curves were drawn, and the corresponding false-positive rate (FPR) and true-positive rate were calculated for each group. From the total true-positive rate and FPRs, the probabilities of illness for positive and negative results were calculated, for severe pancreatitis prevalence from 0 to 1. Last, the area below the curve and the ratio between this and that of the "perfect test" were calculated as a measurement of information content.Data Synthesis:Ranson's signs demonstrated poor discriminant power in both predictions: "d" values were 1.200 (95% confidence interval, 1.083-1.318) and 1.302 (95% confidence interval, 1.046-1.559), respectively. The lack of homogeneity in group S (Q = 58.737;p= .0000032) can be explained by the presence of three outliers. The summary curves showed, for low FPRs, a higher sensitivity of clinical judgment; Ranson's signs reached useful sensitivity only for high FPRs. No differences between groups in the area below the information content curves were found.Conclusions:Ranson's signs showed a poor predictive power. The information content did not differ from that of clinical judgment.

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID